An Introduction to Drilling Offshore Oil Wells

byBenonApril 2, 2010

Introduction: With the price of oil steadily climbing and President Obama’s promise to open up more of the United State’s Coastline to offshore oil and gas drilling, I thought it would be fun to explain how oil and gas wells are drilled in the ultra-deep waters of the Gulf of Mexico and beyond.

My goal is to make this series as non-technical as possible so that anyone will be able to understand the basic concepts, challenges, expenses, environmental impacts, and financial risks of drilling offshore oil and gas wells.

If you have any questions on the basics of drilling offshore oil and gas wells, please don’t hesitate to ask a question in the comment box at the end of this article!

How Oil Companies Decide Where to Drill Offshore Oil and Gas Wells:

When it comes to deciding where to drill an offshore oil or gas well, oil companies look at a variety of information and then make an “educated guess” on where the best spot might be to begin drilling.

First, an oil company will hire a survey boat (seismic survey vessel) to scan underneath the sea floor to look at the various rock and sediment formations in the ground.

Scientists on the survey boat fire sound waves from a “gun” towed several miles behind the boat. The sound waves reflect off the various layers of ground underneath the sea bed and echo back to the survey boat. High tech computers on board the survey boat are able to turn these reflected sound waves into an image showing the various features of the earth directly below.

Geologists who specialize in identifying oil and gas look at these images to see if there are any areas where oil might be present. As this technology has improved over the years, survey boats are able to create 3-D images of the ground which has significantly improved the geologists’ ability to identify potential oil deposits.

Environmentalist argue that sound waves used by these survey vessels adversely affects marine life, and there are currently many studies underway to quantify their concerns. Although I sympathize with the activists and more importantly the animals, my personal opinion is these sound waves are nothing more than a momentary nuisance to the marine life.

The Success Rate for Drilling Offshore Oil Wells:

As technology has advanced, and our understanding of oil geology has improved, oil companies are getting much better at finding producible oil reservoirs in the ground. Two decades ago nearly one out of eight exploratory (or wildcat) oil wells was successful. Today nearly 1 in 3 of all exploratory oil and gas wells are successful.

Its a good thing too! As wells are drilled in deeper water, and deeper into the earth, an offshore oil well may cost $70,000,000 or more to drill! Once a well has been successfully drilled, an oil company may spend an additional half billion dollars to get the oil back to a refinery.

How Oil Companies get Permission to Drill in a Particular Area:

The United States has exclusive rights over any oil or gas found up to 200 miles from it’s coastlines. In areas where this 20o mile “economic zone” overlaps another country’s economic zone (such as the case with Mexico in the Gulf of Mexico), the overlapping zones are split evenly between the two countries.

In the Gulf of Mexico (and other areas of the world) the seafloor is divided into rectangular “blocks” approximately 2 or 3 miles square. There are thousands of these blocks in the Gulf and any company wanting to drill within a particular block must own the mineral rights to do so. So how do they get the rights you might ask?

On the United States’ side of the Gulf of Mexico, the Minerals Management Service (MMS) is responsible for overseeing all offshore oil and gas drilling including leasing the mineral rights to these blocks. MMS is a bureau of the Department of the Interior and collects over $5 Billion in revenue each year from the sale of inland and offshore oil and gas leases.

When oil companies decide they want to drill in a particular block, they must first make sure no one else owns the rights. To manage this, MMS has periodic auctions for any unleased land eligible to be drilled on. Oil companies can submit their bids to MMS to drill in a particular block and if they are the highest bidder, they are usually given the right to do so.

The higher the probability that oil exsists on the block, the more an oil company is willing to bid on the lease. As an example of how high these bids can get, Anadarko and Mariner Energy recently paid over $52,000,000 for one single block (Walker Ridge 793) in the Gulf of Mexico.

The Different Types of Offshore Oil Drilling Rigs:

Once an oil company obtains the rights to drill within a particular lease area, they must find an oil rig that is capable of drilling the well. As the search for oil has expanded into deeper and deeper water, oil rigs have become larger and more sophisticated, and the people operating them are highly skilled.

It’s interesting to point out that most major oil companies do not own their own oil drilling rigs. Instead, they outsource the job of actually drilling the oil well to a drilling contractor who has the people, equipment, and expertise to drill oil wells in the safest, most efficient, and environmentally friendly way possible. The largest of these oil drilling contractors is Transocean, but Diamond Drilling, Pride, Frontier, and Sea-Drill also have a large presence in the industry.

There are several different types of oil drilling rigs. I’ll give you a brief overview here but the two major types involved in deepwater offshore drilling are the last two.

Jackups:

Jackup oil rigs are limited to shallow water drilling (typically less than 300 feet). As their name suggests, these units are towed to a prospective drilling lease and then “jacked up” into position.

A jackup typically has three or four long legs (up to 350 feet high) that run through the hull up into the air. Once the jackup is over the proposed well location, each leg is jacked down to the sea-floor until they support the weight of the entire unit lifting it out of the water.

Once the weight of the barge is fully supported and the unit begins to rise out of the water, the legs are jacked down further until the unit is 10-40′ in the air. When all safety checks are complete, and the unit is found to be secured, the unit will switch to drilling mode and begin drilling the well.

Semi-Submersibles:

Semi-submersibles are what most people think of when they hear the term oil rig. The oil rig shown in the beginning of the movie “Armageddon” was a semi-submersible.

So why is this type of oil rig called a semi-submersible? Well, once these units are over the proposed well drilling location, they flood their huge ballast tanks with seawater and partially submerge below the surface of the water.

What you typically do not see is that most semi-submersibles are built with two huge pontoons on the bottom. These pontoons are what provides the buoyancy to keep the unit floating. Since the majority of a semi-submersibles buoyancy is located well beneath the surface of the water, semi-submersibles are very stable even in 10-20 foot seas.

Semi-submersibles can maintain their position over a proposed oil or gas well two separate ways.

The traditional method of keeping a semi-submersible on location is through the use of anchors. Up two twelve anchors are run out away from the unit and set on the ocean floor. The tension in the anchor chain or cable is increased by use of a large winch and once the oil rig is positioned over the well, only a few minor adjustments need to be made to keep the unit on location.

Semi-submersibles were typically limited to drilling in water depths less than 2000 feet, but today’s advanced semi-submersibles can be anchored in water depths over 8,000′.

The second method of keeping a semi-submersible on location is through whats called a dynamic positioning system or “DP” system.

With a DP system, the semi-submersible uses position information from high tech GPS systems and radio beacons on the ocean floor to constantly monitor its position. If the DP computer detects that the oil rig is drifting off location (either from the wind, waves, or current), huge thrusters underneath the rig will apply thrust to push it back over the well.

It’s not unusual for a modern dynamically positioned oil rig to stay within 5 feet of a wellhead more than a mile below the surface of the water over a 24 hour period.

While semi-submersibles have the advantage of being very stable in rough environments, they are somewhat limited by the amount of equipment and supplies they are able to store on board.

Drillships:

Over the last 15 years, drillships have been built to meet the growing demand for highly capable ultra-deepwater drilling rigs.

Built on traditional ship bodies, these drilling rigs are massive in size and can stretch nearly 3 football fields in length. Although they are not quite as stable as semi-submersibles, drillships more than make up for it with an a much larger storage capacity.

Today’s generations of deepwater drillships use the dynamic positioning system (mentioned above) for maintaining their position.

Drillships are capable of working for extended periods without the need for constant resupplying.

Another benefit of a drillship (especially those operating in the Gulf of Mexico), is their speed and maneuverability. Where most semi-submersibles are evacuated and left to the mercy of the environment when a hurricane approaches, drillships can secure their operation and sail out of harms way. This simple facted alone has saved oil companies 10’s of millions of dollars over the last 5 hurricane seasons.

The First Step: “Spud-In”

It’s taken a lot of work to get to this point but we are now ready to begin drilling our “hypothetical” oil well. We’ve decided where to drill our well and leased the mineral rights from MMS, we’ve looked at the success rates for drilling an offshore oil well, and we’ve decided on what type of oil rig to use to drill our well (for the sake of this article, we’ll be using a drillship).

The first step in actually drilling a well is called “spudding in“. When drilling oil wells in deep water (>1000′), this involves forcing 300-400 feet of 36″ diameter metal tubing called “casing” into the ground. This 36″ diameter casing will form the backbone of the well and provide the support we’ll need for the remaining phases in our well construction plan.

The 36″ casing is lowered to the seafloor by “drill pipe”. Each section of drill pipe is anywhere from 30-45 feet long and about 6″ in diameter. The drill pipe is connected end to end and gradually lowered down into the well and back up to the surface as needed.

To help speed up the time connecting hundreds of sections of drill pipe together every time you want to lower a drill bit, casing, or other piece of equipment into the well, the drill pipe is stored in the derrick three or for sections at a time. This saves the drilling companies time and money.

Each section of drill pipe is called a “joint“, and when two or more “joints” connected and “racked back” in the derrick they are then called a “stand“.

Fancy Drilling Lingo:

Joint: One section of drill pipe.

Stand: Two or more sections of drill pipe “racked back” in the derrick.

Racking Back:The process of storing one or more “stands” of drill pipe in the derrick.

Because the seafloor in the Gulf of Mexico is covered in a deep layer of loose sediment (deposited by the Mississippi River), you don’t really need to “drill” the 36″ casing into the ground. In most cases, pumping sea-water through the end of the casing using the ships massive pumps is all you need to do to get the pipe to settle into the ground.

As the casing gets deeper and deeper into the ground, some rigs use giant “hammers” to pound the casing into the ground to the desired depth.

When the 36″ casing is set to the correct depth, we unlatch the drill pipe from it and pull the drill pipe back to the surface so that we can get the next section of casing and proceed to step 2 of our well drilling program.

The Second Step: Drilling a Hole for Second String of Casing

The next step in our well drilling plan is to lower a drill bit down inside the 36″ casing we just set into the seafloor. Once the drill bit enters inside the 36″ casing we’ll drill 2000-3000′ into the ground. We need to make sure the bit we are using is large enough so that we can run our next section of “casing” into the ground (running the casing inside the 36″ casing).

Although my picture above of a “drill bit” cutting through the earth is a little crude (I’m not a very good artist), I’ll do my best to explain how the drill bit actually cuts through the earth.

As you can see (sort of) in my lovely drawing, the drill bit is connected to the drill pipe which runs all the way back to the surface of the water to the drill ship.

As the bit is rotated in the well bore (the hole that is cut into the ground), high pressure drilling fluids called “mud” is pumped down the center of the drill pipe and out through nozzles in the drilling bit. The drilling fluid is represented by the solid red coloring in the drawing above.

As the drill bit cuts away at the rock formations, the drilling fluid then carries the chipped rock pieces (represented in yellow) out of the hole to prevent them from building up on the bottom of the well.

Drilling fluid, or “mud” as it is referred to on a drilling rig, has several other important functions besides clearing out rock bits from around the bit.

First, it keep the bit cool as it turn through layer after layer of hard rock formations. Second, it keeps the bit and the drill pipe lubricated to help keep it from getting stuck in the ground. Perhaps most importantly, the “mud” helps prevent the well from caving in or “taking a kick”. This is a very dangerous occurrence which we’ll talk about more in a little while.

After you’ve drilled deep enough to “run” your 22″ casing, you bring the drill bit and all the drill pipe back to the surface and then begin lowering the 22″ casing back down to the seafloor. Using an underwater Remotely Operated Vehicle (ROV), we are able to line the 22″ casing up so that it will pass through the 36″ casing and into the freshly drilled hole.

This second section of casing we are installing (the 22″ casing) is usually between 1000′ to 3000′ in length.

The Third Step: Cementing the First Two Casing Sections in Place

Once the 22″ casing is set inside the 36″ casing, the two different sized casings are cemented in place. This is accomplished by pumping cement down the drill pipe (represented in yellow in the picture below) and out through a special nozzle on the end of the pipe.

This is a very critical step in the operation. The cement must be mixed very carefully and every effort is made to ensure the nozzle is lowered to the correct position inside the casing. Once the cement has been pumped down the drill pipe and back up around the sides of the casing (filling in the space between the casing and the drilled well hole (see picture above) it takes anywhere from 4-12 hours for it to harden up or “set”.

If a mistake is made during the cementing operation, it can be very costly to fix.

The Fourth Step: Connecting the Blowout Preventer (BOP) and Marine Riser On Top of the Well Head

Formations in the ground are under tremendous pressure. When you are drilling in areas where oil, water, or gas may be present, there is a possibility this pressure may escape out through the well you are drilling. When this happens its called a “blow out”.

In some ways, the concept is very similar to popping a balloon. Think of the air inside the balloon as a formation of oil. When you poke through the surface of the “formation”, the air escapes out the hole and more often than not, the balloon violently explodes.

To control these formation pressures, a large underwater control valve called a Blowout Preventer (BOP) is placed on top of the wellhead. This is why its very important to have run the first two sections of casing and properly cemented them in place.

The BOP sits directly on top of the wellhead on the ocean floor. In the event a blowout or “kick” occurs, giant valves inside the BOP can seal off the well keeping any oil, gas, and any excessive pressure contained within the ground.

If not for the blow out preventer, oil and gas would escape directly to the sea causing tremendous damage to the environment. Ensuring the BOPs are properly maintained and tested is one of the highest priorities of both the drilling contractor and the oil company involved in drilling the well. BOP testing is also closely watched by the Minerals Management Service (MMS) mentioned at the beginning of this series.

The BOP is rigidly connected to the drilling rig by way of marine riser. Drill pipe can be lowered down through the marine riser, through the BOP, into the wellhead, and then down into the well to drill deeper into the ground. As the drilling fluid or mud is pumped through the drill pipe and out through the drill bit, it circulates all the way around up through the marine riser back to the oil rig.

As mentioned earlier drilling fluid helps clear the rock bits or “cuttings” that are constantly being chipped away as the drill bit drills deeper into the ground. Marine riser allows these “cuttings” to be brought back up to the oil rig to be collected and disposed of.

In the drawing above, you can see the drilling fluid (red) being pumped down the drill pipe. Once the drilling fluid or “mud” shoots out of the nozzles in the drill bit, it returns back up the marine riser (green) in the space between the drill pipe and the inner wall of the marine riser.

This is especially helpful to the environment to prevent any contaminated cuttings from affecting the local marine life.

Once the mud returns to the drilling rig, the cuttings are filtered out and the mud is reused. Being able to reuse drilling mud is very important because it can be extremely expensive to buy. Oil companies can spend millions of dollars for drilling fluid or “mud” on every well they drill. Who knew that playing with mud could be so lucrative?

Why are Blow Out Prevents (BOPs) and Marine Riser so Important:

We talked a little bit about Blow-Out Preventers and Marine Riser in the last few paragraphs. Now its time to explain why this equipment is so important to the overall well drilling operation.

As we mentioned above, oil well blowouts or “kicks” as they are sometimes called, are uncontrolled releases of pressure from underground formations into the well hole or “well bore“.

These “blow-outs” are not only bad for the well, but they can be extremely bad for the drilling rig and everyone on board if they are not properly dealt with.

Many oil rig workers have lost their lives to explosions and fires when uncontrolled gases from blow-outs escaped from the well up to the surface of the water.

Drilling fluid is much heavier than sea water. In some cases it can be more than twice as heavy as seawater. This is helpful when drilling a well because it’s weight creates enough pressure to keep any pressure in the oil or gas formation from escaping back up through the well.

The heavier the drilling fluid you use when drilling a well, the less likely you are to have formation pressure escaping back up into the well and up your marine riser.

On the other hand, if the drilling fluid you are drilling with is too heavy, you run the risk of breaking or cracking the well. When this happens, your drilling fluid begins leaking out into the underground formation. This is also very bad, because without being able to circulate the mud back up through the marine riser, you will be unable to drill any deeper.

As the well is drilled deeper and deeper, the mud weight operating window gets smaller and smaller.

The Fifth Step: Drilling the Remaining Sections of the Well

The remaining sections of the well are drilled the same way as the 22″ casing was drilled in the earlier step only now the cuttings and mud are circulated back up to the drillship to be processed.

The drill crews will drill deeper into the ground so that the next section of casing can be run and cemented into place. There is no set limit on how long each section of casing will be, this decision is left up to the drilling engineers that have closely analyzed the survey data and any data from nearby or “offset” wells.

As the drill bit continues to make its way towards the oil or “pay zone”, the drilling crew closely monitors the amount of fluid in the storage tanks as well as the pressure of the formation to ensure that the well is now experiencing a blow-out or kick.

If it is determine that the well is experiencing a “blow-out” or kick, the Blow Out Preventer (BOP) control valves are closed off and the drill crew must take measure to stabilize the well. To stabilize a well that has experienced a “kick”, the drill crew is usually able to control it by pumping heavier drilling fluids into the well to “force” the kicked pressure back into the formation.

Determining if a Well has a Produceable Amount of Oil or Gas:

Once the geologists are happy with the depth of the well, a series of test called “logs” will be conducted to determine how much oil and gas (if any) is present in the formation. The process is called logging because the information is “logged” into a database as it is collected.

This is accomplished by sending high tech measurement devices into the hole that can detect various features of the formation.

Using a combination of sound wave tools, electrical wave tools, and radiation measurement instruments, geologist are able to take readings inside the well which will assist them in determining the presence of oil.

However, just because there is oil or gas at the bottom of the well doesn’t always mean it is worthwhile to pump it out. Oil companies must decide whether the amount of oil present in the formation is worth investing hundreds of millions of dollars in additional equipment to pump it out and back to a refinery.

In some instances, an oil company may decide to “test flow” a well to help determine how much oil is there. When test flowing a well, oil is allowed to flow up from the well into storage tanks. The pressure is recorded and if it remains at certain levels over a certain amount of time, the oil companies may decide that investing more money to “produce” the well is worth the costs.

Conclusion:

As you can see, the process of drilling an oil well (even when boiled down to the most basic elements) is very complicated and there are many opportunities for things to go wrong. Oil companies can invest over $100,000,000 in a single well only to find out there is no oil present.

There are substantial risks involved with drilling an oil well, but the rewards can be tremendous. One successful oil well can easily cover the expenses of multiple dry wells (sometimes referred to as dusters).

By no means is this article intended to be a comprehensive guide into the various challenges and risks of drilling offshore oil and gas wells, but I hope that it has given you at least a basic appreciation of how they are drilled.

Thanks to all of you who comment on this article! Comments are now closed!

Would someone please explain to me how a “relief” well in any way removes pressure
from the main well? My understanding from hydraulics is that a pressure source will deliver at source pressure to any number of parallel branches. Two channels could double the flow rate without diminishing the first. And some type of obstruction in the first pipe will be necessary to prevent any mud or cement injected through the relief well from being ejected up the first. A youtube video said there’s a lake of oil forming above the main chamber in rock strata under the Gulf from cracks & fissures around the bore. Also Lindsey Williams said the pressures are far above those anyone in the industry had seen, 100k psi.

First time I heard the 100k PSI number, hope it is wrong. If not, we have big problems. As for the relief wells, they are aiming at intercepting the current shaft -above- the reservoir. The theory is that by providing a second port with no restriction, you can then attempt to block the first port (the original well) without the pressure going sky high. The limiting factor is the size of the original well bore where it enters the reservoir. Current “guess” (as no information is being directly released) is that when the first top-kill was tried, the pressure inside the casing went through the roof and secondary seepage showed up confirming a casing problem below the seabed. The top-kill was aborted as oil rushing through any breach will tend to erode the casing and make things worse. I cannot imagine a bottom kill working using the relief well. With the relief well in place and oil being pumped out of it, I could see then using a top kill on the original well.

Was looking over some of the pressure data at http://www.energy.gov/open/oilspilldata.htm and they list the ambient water pressure at 2,250 psi and a well head pressure at 4,400 psi measured below the BOP. Given that the BOP is wide open, we can assume that number would be much higher if the flow was restricted. (Readings taken May 25, 10.) Still, that is over a ton per sq over the ambient with little to no restriction on flow.

what makes them think by nuking the oil well would stop the oil flow don,t forget the gas well was on the surface not under water i think it would only make matters worse than it already is by fracturing the ground with a nuke blast it would then let the oil to pass up to surface through the fractured sea bed .i mean come i,m no rocket scientist and know what will happen are you,s trying to wipe us off the face of the earth or what i have an idea that would stop it but as i read on bp,s site they would,nt pay for an idea that would definitely work so i,ll keep the idea to myself and hope they figure it out

Hi,
I’m not not a drilling engeneer but just want to put here some idea helping to stop oil flow in the gulf of Mexico.
So I don’t have any guarantee if this would be technically possible *gg* but listen:

What about drilling a second hole next to the existing one and hit the first/damaged oil well directly by the side with another kind of collecting pipe few hundred meters under the sea ground.

Now start with catching up all coming up oil/gas/mud into the second well (under control by some new BOP), to reduce oil flow/pressure in the first damaged well, it will make it easier to close the old hole without having 650bar of pressure and 150°C of temp or whatever it is really blowing out?!?

When lowering the pressure in the old well it would make it possible to put some kind of plug into the hole (deep inside) and fullfill the rest of the well until up to the sea floor with concrete or something else.

You should anyway have the flow under control by the new second well with a BOP and then –> SHUT IT!

Pretty much what they are in the process of doing. As much as BP has worked to destroy our confidence in them, I still trust them (regarding the wellhead) more than I do the Gov. They realize they unleashed a tiger, and they are the ones wearing an overcoat made of fresh raw meat. They are racking their brains looking for a good solution. They are also not saying much for fear of adding more lawsuits. I am keeping an eye on their ROVs and blogging what I see in the news section of my energy site: http://energy.velmadinkley.com/

That’s a whole-lot-of-pressure. And I wasn’t aware that ‘down-hole’ damage had been confirmed. I don’t see how a relief well + bottom kill, a new BOP, or my lead weight, is going to be effective. It seems that any of those efforts will exacerbate the damage and make things worse. Are we seriously screwed?

Hope not. I have a hard time buying the 100k number. We know the mud was keeping things in check, but the seawater did not. I don’t know the weight of 23,000 feet of mud (18k + 5k), but the number I keep hearing is between 11k and 15k psi.
Since the blowout, very little confirmable information has come out. The “down-hole” theory is based more on the actions BP has been taking since the attempted/aborted top kill. The open flow top to bottom pressures on the BOP is a little spooky though.

Good article. The drill hole could get very narrow in diameter with too many smaller sections of casing.

I asked BP why they couldn’t just bolt another valve on the flange on top of the BOP then close it. Seems so obvious but it must be because they are afraid the whole casing will blow out. Or else there exist holes in the current casing through which oil would escape instead. This situation has the potential to get much worse in my opinion.

Why not install a 10′ diameter casing over top of (around) the 3′ casing, to a depth that when filled with mud. Then add the last section to the casing that would have it’s own BOP(s) (wide open) then slowly shut the valve and or siphon off the oil in a controlled matter and acually get to use the oil? No, I don’t care how much that might cost! Maybe we could bag the health care fiasco and use that money for this effort?

BP has removed the cap and unbolted the flange on the BOP. What has been revealed is that in addition to the strong flow from the well bore, there is an even stronger flow out of the drill pipe. This is a problem as the drill pipe extends all the way to the bit, which is below where the relief wells are planned to intercept. Short of pulling the 13,000 feet of drill pipe out, they will not be able to achieve a top or bottom kill. I posted a screen capture of this in the news section of my energy site:http://energy.velmadinkley.com/

As an old Baroid mud hand I was wondering if you knew what mud weight they had before the blowout. Also what was the TD of the hole.
At what depth is the relief well going to intercept the old hole?
Are they going to try to mud it up and kill it then try an overshot and pull the drill pipe or are they just going to cement it up.
Thanks for your time and opinions.

Hopefully this madness has ended -how ever The nuke idea was to cause an under ground cave in – By placing a high explosive – 500 to a 1,000 ft below the surface you would seal off the well by the heat and cave in effect. A SMALL nuke explosion at the well head its self was not the idea –

if anyone out there knows, i would like some early info. 1. how tall is the well head off the ocean floor, 2. how large are the underwater vehicles, i am guessing that there are two different types, (one) is largest for the fixing of everything down there, and the others, the ones appearing on the animation picts which i think are just for lighting. the reason for my inquire is because of these animated images. it will show 4 or 5 of these submersibles hovering around the well head, making it to appear very large, or these subs. are really very small, and are there only to light things up? my querry. thanks for any help out there… jim

It is true, not many (if any) are checked. In the past three months many tar balls and other oil products have washed up in many places and when they were tested they were found to not be from DWH. This is a good indicator that something else is leaking. It is yet to be determined if it from closed well seepage or unreported spills from other rigs. Probably both.

As for DWH, they are now playing “jack in the box.” Decisions based more on politics then science. Harvest or kill are the options. Leaving it pressurized should be the last option, used only if a hurricane comes to town.

I’m a dummy on all this, but I am interested in this comment by germeten:

“Would someone please explain to me how a “relief” well in any way removes pressure from the main well? My understanding from hydraulics is that a pressure source will deliver at source pressure to any number of parallel branches.”

I may have missed it in the responses–and maybe I don’t understand the question or issue–but is it true that the pressure would remain the same with a second ‘tap’ into the well?

Imagine a one inch pipe going into a “Y” and exiting as two 1″ pipes. If both output pipes were blocked, then the pressure would be the same at any location. If one of the two exits were unblocked, then the pressure would drop quite drastically at the second outlet cap. If you opened both, the flow rate from the two outlets would be 1/2 the flow rate of the inlet. The relief well is the second exit. If allowed to flow, the head pressure on the main well would be much lower than if there were no exit, as the flow is restricted by the bottom length of casing.

As it stands now, there is great question as to what their next step is going to be. The “bullhead kill” would render the relief well unneeded. The “bottom kill” would allow them to force mud down the relief and into the main well only at a much higher pressure due to the 18,000 foot head. Talk is of using a 14 to 17 pound mud-weight. Too tired to do the math on 18,000 feet of mud, but it is safe to say that if 14 pound mud kept the well in check before the blowout, and the pressure is lower now, this should be an easy kill as we now know the pressure of the contained well.

Seems like a waste to kill a very productive well, but the PR backlash for not doing so is off the scale!

All they are doing is interecepting the well bore closer to the bottom (near the oil formation) and filling the column with heavy mud. As the mud is forced back up through the flowing well it the hydrostatic pressure will build until it overcomes the pressure of the oil coming out of the formation. At this time the well will be “static” and cement can be pumped into the column to then seal it off.

Oil will not come up through the relief well either because there will be heavy drilling fluid (mud) in it as well!

You know there is much talk of pressure, Y’s and all this, but one thing that is not on people’s minds is something pretty important. I used to have some property with a ditch on the edge of it. My neighbor wanted to enclose the ditch in 10″ pipe saying he’d pay for it, all I had to do was agree, so I did. Now once the pipe was installed it probably dropped about 35 feet from the source irrigation ditch. Okay so I tried hooking up different types of watering devices to use on my garden, but none seemed to work because it just didn’t have enough pressure. Now mind you that if you were to unscrew one of the faucets which had a 5/8″ hole, it would literally almost knock you over and squirt a 5/8″ jet some fifty feet high, now capping or putting the cleaned out faucet (we had crawdad’s which would swim into the faucet) back on was another story and as I tried this many times during a summer I learned something that has nothing to do with pressures or the height from which the water comes and that was momentum. Okay so if my neighbor was not using any water, basically no sprinkler would work of any kind. But if my neighbor opened up the 10″ pipe say 1/2 way, well I could get all kinds of sprinklers to work, seemingly because of the momentum of the flow. So anyways I designed, or reworked a rainbird sprinkler so that its splashing hit to the outlet was timed to the length of the pipe, sort of like resonant frequencies and all the sudden I could use 6 rainbirds.

My point is that the pressure is not all that is trouble, the 3 mile long flow at high speeds, constantly going from smaller pipe to bigger pipe is the problem I see. For one the compressed natural gas will by nature tend to expand as it goes from smaller casing to larger casing as this is the method by which your a/c in your car works, and as the gas expands it pushes harder and harder on the oil increasing it’s velocity, thereby neutralizing the effect that going from smaller to bigger would have on the oil itself. Which would be by nature to slow down, but you must remember the weight and velocity of said oil/gas mixture because when you go to slow down or stop the flow you will be dealing with the momentum of many hundreds of thousands of pounds of oil and the pressure. In my experimenting with my irrigation pipe I learned that if you grabbed hold of the lever that controlled the 10″ end of the pipe and opened it up full throttle and then simultaneously had a hose or sprinkler trying to work, well when you slammed close the valve the pressure or flow of water would increase by at least 10 fold for a moment as the wave pulsed back up the pipe, also it would physically shake the ground and flex the hell out of the pipe buried under 3 feet of dirt lifting and making cracks all around the pipe all the way back to the ditch. So I can tell you that as they try to shut down the flow they will be dealing with alot more than just pressure and it has to be done slowly and without jolts as those jolts would send shock waves back down the well bore and could possibly vibrate or crack the connections. I can say this with all confidence, if they nuke the well it surely needs to be in stop flow condition when they do it because it that well was flowing full flow as it was before they closed it off, then the jolt of the nuke slamming shut the bore hole would or could have enough energy to either blow the casing or crack the cement job even worse.

I understand that many of you guys won’t understand what I was trying to convey because you are on city water or well water and are not usually dealing with the situation I spoke of, but I promise you that the momentum of said flow is more dangerous than the pressure. Now as far as the 100,000PSI figure, I think we now know that is bull, a simple math calculation shows that if it had anywhere near that pressure it would simply shoot the bop off the top and go about it’s buisness, do the math and you’ll see it could lift some 31,000,000 pounds, and anything of less weight like the 900,000 Lb bop would simply be blown out of the way like when you blow on dust in your computer case, not true, but 6900PSI is problematic enough, along with the flow’s momentum I’d say that if they can open the top part very slowly and push the mud up from the bottom at the same rate of flow out of the top and then close it off once the mud comes out the top, then that’s what they’d better do, because like it or not people, there is a prophecy in your bible which says this aint over yet. I pray for both though, I want all the prophecies to come true so that this beast of a world will go bye-bye, but at the same time I was raised on cousteau and taught to love that which you can’t see under the ocean surface and to love whales and coral and fishes and I really hate to think of man’s uncontrolled lust and desire for oil could be the end of a 1/3rd of our oceans. All these fish these guys in the gulf gather are considered unclean and so I won’t even flinch to think crab, oyster, crustaceans etc won’t be available, this to me is a good thing, just like the swine flu bs caused the removal of every single pig in the middle east. You like bacon, well make sure you eat your share before you make your pilgramige because they don’t serve bacon no more in the middle east, not even a pig in a zoo! So I feel for the loss of wages or income, but as for the stuff they call food, well since mankind won’t stop eating that which the creator made to clean up the oceans of all the crap we send down river, I guess he has his ways of getting it out of your mouth, and for that I praise him. Whoever thinks this is over, think again, there is much more to come and as with all the prophecies, none will be foolproof or anything of the sort, all of them will be as they always have been, if you don’t want to believe, then whatever is going on will always be seen by the unbeliever as laughable, but to the studied eye, obvious and anticipated from the time the teaching was instilled. Peace

Can you tell me how they can drill a relief well and steer it so that it intercepts a 6″ diameter shaft 23,000 feet down? How do they find the old well shaft? How do they control/steer the new shaft to intercept?

The above discussion as to how the well is drilled answers a lot of my questions.
I would really like to see pictures of the drill “bit” itself. I’m trying to imagine what it looks like.
Can you refer me?

How soon after a well has been sucessfully drilled, does the oil from the well, enter into the international supply pool? If not right away, how long can a well be capped and lay dormant
before actually being tapped for use? How many wells such as this may exist? Serving in the meantime as real assets to owners of these properties. Thank you.

How soon after a well has been sucessfully drilled, does the oil from the well, enter into the international supply pool? If not right away, how long can a well be capped and lay dormant.
before actually being tapped for use? How many wells such as this may exist? Serving in the meantime as real assets to owners of these properties. Thank you.

Thanks for the question Joseph! From the time an offshore oil well is successfully drilled and proven to be “viable”, it could take between 5-7 years to actually get the oil into the “supply chain”. There are several reasons why this takes so long.

First, the well must be “completed” which means another oil rig or plaform will come along and prepare the well to actually pump oil. This involves setting screens inplace (to keep sand and stuff out), “fracking” the well to improve the efficiency of the well, and installing sub surface “safety valves” to automatically shut in in the event of an emergency while the well was producing.

Next we have the issue of how we are going to get the oil to “land”. This is most likely going to be done by underwater pipeline which could take anywhere from 1-3 years to fully install.

Next, if the well is in a relatively remote area (say 30-40 miles or more away from other production platforms, you’ll need to build a production platform to “process” the oil as it is pumped out of the ground. This too could take anywhere from 2-4 years.

Hay! I reiterate some ideas which I submitted to this site back a few mo. after the BP BOP “failed”.
I commented about how this fitted the anti fossil fuels “green” and environmental bent of the Obama history. That was how long ago? Look at it now!
Sure, he (Obama) ended the moratorium on new wells. What happened right after that? After all the court crap where the judge found the Obamation in contempt? TWICE? Well he rescinded the moratorium and then what?! He restricted the new licenses to ONE! Guess who he did that for? B flippin’ P!
This makes things stink even worse as Obama had to have someone on the inside to create all the “failures” which caused that mess. Not to mention the way his environmental “protection” agency befouled any attempt to mitigate the damage which could have been much less than what it turned out to be! And, they blocked , blocked, blocked anyone with a good idea! And, don’t forget, we don’t have any kind of evidence (that I’ve seen) to be confident at what the damage is?
But, that’s all moot now. Obama has demonized “Big” oil way beyond repair. In the progressive mind and ABC, CBS, NBC-ville!
HAY! Does anyone else see this assault on the economy? The nation? Not to mention the Obamanations assault on small business and the quantitative “easing” which is pissin’ our creditors off so bad, and the spend, spend, spend and spend and hide crap!
There is NO FLIPPIN’ WAY this could be some inexperienced guy just findin’ his “sea” legs, don’t ya know? This is DELIBERATE! This Obama may’ve been born in the USA, but he is so un-American in all his actions!
Come on! Somebody out there has to see this!
RSVP @ sk.atarah808@gmail.com

YOUR SITE IS THE BEST QUICK BASIC EDUCATION ON OCEAN OIL WELLS I’VE FOUND. ARE THERE ANY EDUCATIONAL FILMS ON DRILLING OCEAN OIL WELLS? THE PRICE OF GAS IS HAVING SO MUCH INFLUENCE ON EVERYONES LIFE I THINK EVERYONE WOULD LIKE TO KNOW MORE. THE COSTS SPENT INTO AN OCEAN OILWELL ARE TOTALS MUCH HIGHER THAN I EXPECTED TO HEAR. ALLOT OF PEOPLE HAVE BEEN OUT OF WORK IN OREGON. DO OIL COMPANIES HIRE MANUFACTURING COMPANIES TO MAKE PARTS FOR THE DRILLING RIGS? WOULD OREGON MANUFACTURING COMPANIES BE ABLE TO MAKE SOME OF THE PARTS FOR THE OIL DRILLING RIGS. IN THE 1990S OREGON AND WASHINGTON HAD A CONST BOOM THAT WAS SPENDING MILLIONS OF DOLLARS IN OR-WA. THAT SPENDING RESULTED IN ALLOT OF JOBS. IF OIL COMPANIES WOULD SPEND SOME INTO OR-WA MANUFACTURING IT WOULD GIVE THE AREA A BOOST SIMILAR TO THE CONST BOOM. THE OIL WELL COSTS ARE SO HIGH IT SOUNDS LIKE THEIR MANUFACTURING AREAS MUST HAVE BOOMING ECONOMIES.

Think that fuel would be cheaper if we drilled for and used America’s oil? Oil companies pay around $18/barrel to get crude out of the ground.

There are four giant oil companies that are making a play to own, not just all the oil, but virtually all energy sources on the planet. They are Royal Dutch/Shell, Exxon Mobil, Chevron Texaco and BP Amoco.

These companies control crude oil from the Saudi well-head to the American gas pump and profit from every step of processing, shipping and marketing in between. These oil giants who capped wells in Texas and Louisiana- and moved production to the Middle East pay Bangladeshi, Filipino and Yemeni workers $1 a day to work the oil rigs.

They’ve also invested in war? Shell owns 34% of Petroleum Development Oman in partnership with Exxon Mobil. Saudi ARAMCO, the Iranian Consortium, Iraqi Petroleum Company, Kuwait Oil Company and the ADCO in the United Arab Emirates all represent the Big Four. In Iran, Iraq and Libya these cartels were nationalized. That’s why the Rockefeller/Rothschild Oil Cartel billed US taxpayers to invade Iraq and Libya, while continuing to threaten Iran. The first oil contract in Iraq went to Royal Dutch/Shell. The 2nd goes to BP and the 3rd to Exxon Mobil.

During the 1970s Big Oil invested $2.4 billion in uranium exploration. They now control over half the world’s uranium reserves. Chevron Texaco and Shell even developed a joint venture to build nuclear reactors. Exxon owns Carter Mining, one of the top five phosphate producers in the world. Phosphates are needed to process uranium.

Shell’s BHP Billiton tentacle announced a $38.6 billion hostile takeover attempt of Canada’s Potash Corp. BHP Billiton already owns Anglo Potash and Athabasca Potash. Ownership of Potash Corp. would give them control over 30% of the global potash market. Potash is a necessary component in growing any agricultural crop.

BP Amoco, through its ARCO subsidiary, has become one of the world’s top six producers of bauxite, from which aluminum is derived. It has mines in Jamaica and other Caribbean nations.

Chevron Texaco controls over 20% of the huge AMAX mining group, the leading producer of tungsten in the US with extensive holdings in South Africa and Australia. Big oil… And this is just the tip of the ice berg.

Has anyone else noticed the incresed amount of anti obama conspirisy theorys? Well I have and I say one thing…… PROVE IT!!! No “truth-teller” conspirisists have given any viable information! And besides, why oil? Haven’t you notice his renewable energy bills? Go spam them with your theorys!! Oh yeah by the way I am a 6th grader. and this was obvious to me. Common people! We’re not kids anymore! Oh yeah and steve or steven? We all know you are both the same person.